Intravascular devices, systems, and methods having separate sections with engaged core components

ABSTRACT

Intravascular devices, systems, and methods are disclosed. In some instances, the intravascular device is a guide wire that includes separate sections with engaged core components. For example, a sensing guide wire can include a proximal portion having a proximal core member and at least one proximal electrical conductor and a distal portion coupled to the proximal portion, the distal portion having a distal core member, a sensing element, and at least one distal electrical conductor coupled to the sensing element, wherein engagement structures of the proximal and distal core members are engaged and wherein the at least one distal electrical conductor is coupled to the at least one proximal electrical conductor such that the at least one proximal electrical conductor is in electrical communication with the sensing element. Methods of making, manufacturing, and/or assembling such intravascular devices and associated systems are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and the benefit of the U.S.Provisional Patent Application No. 61/982,080, filed Apr. 21, 2014,which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to intravascular devices, systems, andmethods. In some embodiments, the intravascular devices are guide wiresthat include separate sections with engaged core components.

BACKGROUND

Heart disease is very serious and often requires emergency operations tosave lives. A main cause of heart disease is the accumulation of plaqueinside the blood vessels, which eventually occludes the blood vessels.Common treatment options available to open up the occluded vesselinclude balloon angioplasty, rotational atherectomy, and intravascularstents. Traditionally, surgeons have relied on X-ray fluoroscopic imagesthat are planar images showing the external shape of the silhouette ofthe lumen of blood vessels to guide treatment. Unfortunately, with X-rayfluoroscopic images, there is a great deal of uncertainty about theexact extent and orientation of the stenosis responsible for theocclusion, making it difficult to find the exact location of thestenosis. In addition, though it is known that restenosis can occur atthe same place, it is difficult to check the condition inside thevessels after surgery with X-ray.

A currently accepted technique for assessing the severity of a stenosisin a blood vessel, including ischemia causing lesions, is fractionalflow reserve (FFR). FFR is a calculation of the ratio of a distalpressure measurement (taken on the distal side of the stenosis) relativeto a proximal pressure measurement (taken on the proximal side of thestenosis). FFR provides an index of stenosis severity that allowsdetermination as to whether the blockage limits blood flow within thevessel to an extent that treatment is required. The normal value of FFRin a healthy vessel is 1.00, while values less than about 0.80 aregenerally deemed significant and require treatment.

Often intravascular catheters and guide wires are utilized to measurethe pressure within the blood vessel, visualize the inner lumen of theblood vessel, and/or otherwise obtain data related to the blood vessel.To date, guide wires containing pressure sensors, imaging elements,and/or other electronic, optical, or electro-optical components havesuffered from reduced performance characteristics compared to standardguide wires that do not contain such components. For example, thehandling performance of previous guide wires containing electroniccomponents have been hampered, in some instances, by the limited spaceavailable for the core wire after accounting for the space needed forthe conductors or communication lines of the electronic component(s),the stiffness of the rigid housing containing the electroniccomponent(s), and/or other limitations associated with providing thefunctionality of the electronic components in the limited spaceavailable within a guide wire. Further, due to its small diameter, inmany instances the proximal connector portion of the guide wire (i.e.,the connector(s) that facilitate communication between the electroniccomponent(s) of the guide wire and an associated controller orprocessor) is fragile and prone to kinking, which can destroy thefunctionality of the guide wire. For this reason, surgeons are reluctantto remove the proximal connector from the guide wire during a procedurefor fear of breaking the guide wire when reattaching the proximalconnector. Having the guide wire coupled to the proximal connectorfurther limits the maneuverability and handling of the guide wire.

Further, a problem with existing pressure and flow guide wires is thatthey require a complex assembly of many discrete components. Thatcomplex assembly process has limitations on design performance of theguide wire. The use of separate conductive wires running down the lengthof the wire reduces the space available for more supportive cores andcan result in numerous issues during use due to poor solder joints withconductive bands, electrical shorts due to insulation issues, andbreakage of the delicate conductive wires.

Accordingly, there remains a need for improved intravascular devices,systems, and methods that include one or more electronic, optical, orelectro-optical components.

SUMMARY

The present disclosure is directed to intravascular devices, systems,and methods that include a guide wire having a separate sections coupledtogether by engaging core components.

The present disclosure provides a more robust sensing guide wire thatavoids the assembly and performance issues of prior sensing guide wires.Guide wires of the present disclosure have one or more transitionsections that facilitate coupling of different portions of the guidewire. Any type of sensor can be connected to guide wires of the presentdisclosure. In certain embodiments, only a single sensor is connected tothe guide wire. In other embodiments, multiple sensors are connected tothe guide wire. All of the sensors may be the same. Alternatively, thesensors may differ from each other and measure different characteristicsinside a vessel. Exemplary sensors are pressure, flow, and temperaturesensors. Generally, any type of pressure sensor may be used with theguide wires of the present disclosure, including piezoresistive, opticaland/or combinations thereof. In certain embodiments, the pressure sensorincludes a crystalline semi-conductor material. Similarly, any type offlow sensor may be used with guide wires of the present disclosure. Incertain embodiments, the flow sensor includes an ultrasound transducer,such as a Doppler ultrasound transducer. The guide wire can include botha pressure sensor and a flow sensor.

Another aspect of the present disclosure provides methods formanufacturing and/or assembling an intravascular device. The methods caninclude providing a proximal portion having a proximal core member andat least one proximal electrical conductor, wherein a distal section ofthe proximal core member includes a first engagement structure;providing a distal portion having a distal core member, a sensingelement, and at least one distal electrical conductor coupled to thesensing element, wherein a proximal section of the distal core memberincludes a second engagement structure; and coupling the proximalportion to the distal portion, including: securing the proximal coremember to the distal core member, wherein securing the proximal coremember to the distal core member includes engaging the first engagementstructure with the second engagement structure; and electricallycoupling the at least one proximal electrical conductor to the at leastone distal electrical conductor such that the at least one proximalelectrical conductor is in electrical communication with the sensingelement.

In another aspect, sensing guide wires are provided. The guide wires caninclude a proximal portion having a proximal core member and at leastone proximal electrical conductor and a distal portion coupled to theproximal portion, the distal portion having a distal core member, asensing element, and at least one distal electrical conductor coupled tothe sensing element, wherein engagement structures of the proximal anddistal core members are engaged and wherein the at least one distalelectrical conductor is coupled to the at least one proximal electricalconductor such that the at least one proximal electrical conductor is inelectrical communication with the sensing element.

Another aspect of the present disclosure provides methods for measuringa characteristic inside a vessel. The methods can include providing asensing guide wire in accordance with the present disclosure, insertingthe guide wire into a vessel, and utilizing one or more sensing elementsof the guide wire to measure one or more characteristics inside thevessel.

Additional aspects, features, and advantages of the present disclosurewill become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure will be describedwith reference to the accompanying drawings, of which:

FIG. 1 is a diagrammatic, schematic side view of an intravascular deviceaccording to an embodiment of the present disclosure.

FIG. 2 is a perspective view of a transition section of an intravasculardevice according to an embodiment of the present disclosure.

FIG. 3 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

FIG. 4 is a perspective view of an engagement structure of a corecomponent according to an embodiment of the present disclosure.

FIG. 5 is a side view of the engagement structure of the core componentof FIG. 4.

FIG. 6 is a bottom view of the engagement structure of the corecomponent of FIGS. 4 and 5.

FIG. 7 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

FIG. 8A is a side view of the components of the transition section of anintravascular device of FIG. 7 shown in arrangement according to anembodiment of the present disclosure.

FIG. 8B is a side view of the components of the transition section of anintravascular device of FIG. 7 shown in another arrangement according toan embodiment of the present disclosure.

FIG. 9 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

FIG. 10 is a perspective view of components of a transition section ofan intravascular device according to an embodiment of the presentdisclosure.

FIG. 11 is a perspective view of components of a transition section ofan intravascular device according to an embodiment of the presentdisclosure.

FIG. 12 is a perspective view of a component of a transition section ofan intravascular device according to an embodiment of the presentdisclosure.

FIG. 13 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

FIG. 14 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

FIG. 15 is a side view of components of a transition section of anintravascular device according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It is nevertheless understood that no limitation tothe scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, systems, and methods, and anyfurther application of the principles of the present disclosure arefully contemplated and included within the present disclosure as wouldnormally occur to one skilled in the art to which the disclosurerelates. In particular, it is fully contemplated that the features,components, and/or steps described with respect to one embodiment may becombined with the features, components, and/or steps described withrespect to other embodiments of the present disclosure. For the sake ofbrevity, however, the numerous iterations of these combinations will notbe described separately.

As used herein, “flexible elongate member” or “elongate flexible member”includes at least any thin, long, flexible structure that can beinserted into the vasculature of a patient. While the illustratedembodiments of the “flexible elongate members” of the present disclosurehave a cylindrical profile with a circular cross-sectional profile thatdefines an outer diameter of the flexible elongate member, in otherinstances all or a portion of the flexible elongate members may haveother geometric cross-sectional profiles (e.g., oval, rectangular,square, elliptical, etc.) or non-geometric cross-sectional profiles.Flexible elongate members include, for example, guide wires andcatheters. In that regard, catheters may or may not include a lumenextending along its length for receiving and/or guiding otherinstruments. If the catheter includes a lumen, the lumen may be centeredor offset with respect to the cross-sectional profile of the device.

In most embodiments, the flexible elongate members of the presentdisclosure include one or more electronic, optical, or electro-opticalcomponents. For example, without limitation, a flexible elongate membermay include one or more of the following types of components: a pressuresensor, a flow sensor, a temperature sensor, an imaging element, anoptical fiber, an ultrasound transducer, a reflector, a mirror, a prism,an ablation element, an RF electrode, a conductor, and/or combinationsthereof. Generally, these components are configured to obtain datarelated to a vessel or other portion of the anatomy in which theflexible elongate member is disposed. Often the components are alsoconfigured to communicate the data to an external device for processingand/or display. In some aspects, embodiments of the present disclosureinclude imaging devices for imaging within the lumen of a vessel,including both medical and non-medical applications. However, someembodiments of the present disclosure are particularly suited for use inthe context of human vasculature. Imaging of the intravascular space,particularly the interior walls of human vasculature can be accomplishedby a number of different techniques, including ultrasound (oftenreferred to as intravascular ultrasound (“IVUS”) and intracardiacechocardiography (“ICE”)) and optical coherence tomography (“OCT”). Inother instances, infrared, thermal, or other imaging modalities areutilized.

The electronic, optical, and/or electro-optical components of thepresent disclosure are often disposed within a distal portion of theflexible elongate member. As used herein, “distal portion” of theflexible elongate member includes any portion of the flexible elongatemember from the mid-point to the distal tip. As flexible elongatemembers can be solid, some embodiments of the present disclosure willinclude a housing portion at the distal portion for receiving theelectronic components. Such housing portions can be tubular structuresattached to the distal portion of the elongate member. Some flexibleelongate members are tubular and have one or more lumens in which theelectronic components can be positioned within the distal portion.

The electronic, optical, and/or electro-optical components and theassociated communication lines are sized and shaped to allow for thediameter of the flexible elongate member to be very small. For example,the outside diameter of the elongate member, such as a guide wire orcatheter, containing one or more electronic, optical, and/orelectro-optical components as described herein are between about 0.0007″(0.0178 mm) and about 0.118″ (3.0 mm), with some particular embodimentshaving outer diameters of approximately 0.014″ (0.3556 mm),approximately 0.018″ (0.4572 mm), and approximately 0.035″ (0.889 mm).As such, the flexible elongate members incorporating the electronic,optical, and/or electro-optical component(s) of the present applicationare suitable for use in a wide variety of lumens within a human patientbesides those that are part or immediately surround the heart, includingveins and arteries of the extremities, renal arteries, blood vessels inand around the brain, and other lumens.

“Connected” and variations thereof as used herein includes directconnections, such as being glued or otherwise fastened directly to, on,within, etc. another element, as well as indirect connections where oneor more elements are disposed between the connected elements.

“Secured” and variations thereof as used herein includes methods bywhich an element is directly secured to another element, such as beingglued or otherwise fastened directly to, on, within, etc. anotherelement, as well as indirect techniques of securing two elementstogether where one or more elements are disposed between the securedelements.

Referring now to FIG. 1, shown therein is a portion of an intravasculardevice 100 according to an embodiment of the present disclosure. In thatregard, the intravascular device 100 includes a flexible elongate memberhaving a central portion 102, a distal portion 104 adjacent a distal end105, and a proximal portion 106 adjacent a proximal end 107. A component108 is positioned within the distal portion 104 proximal of the distaltip 105. Generally, the component 108 is representative of one or moreelectronic, optical, or electro-optical components. In that regard, thecomponent 108 is a pressure sensor, a flow sensor, a temperature sensor,an imaging element, an optical fiber, an ultrasound transducer, areflector, a mirror, a prism, an ablation element, an RF electrode, aconductor, and/or combinations thereof. The specific type of componentor combination of components can be selected based on an intended use ofthe intravascular device. In some instances, the component 108 ispositioned less than 10 cm, less than 5, or less than 3 cm from thedistal tip 105. In some instances, the component 108 is positionedwithin a housing of the flexible elongate member 102. In that regard,the housing is a separate component secured to other components of thedistal portion 104 in some instances. In other instances, the housing isintegrally formed as a part of a component of the distal portion 104.

The intravascular device 100 also includes a connector 110 adjacent theproximal portion 106 of the device. In that regard, the connector 110 isspaced from the proximal end 107 of the intravascular device 100 by adistance 112. Generally, the distance 112 is between 0% and 50% of thetotal length of the intravascular device 100. While the total length ofthe intravascular device can be any length, in some embodiments thetotal length is between about 1300 mm and about 4000 mm, with somespecific embodiments have a length of 1400 mm, 1900 mm, and 3000 mm.Accordingly, in some instances the connector 110 is positioned at theproximal end 107. In other instances, the connector 110 is spaced fromthe proximal end 107. For example, in some instances the connector 110is spaced from the proximal end 107 between about 0 mm and about 1400mm. In some specific embodiments, the connector 110 is spaced from theproximal end by a distance of 0 mm, 300 mm, and 1400 mm.

The connector 110 is configured to facilitate communication between theintravascular device 100 and another device. More specifically, in someembodiments the connector 110 is configured to facilitate communicationof data obtained by the component 108 to another device, such as acomputing device or processor. Accordingly, in some embodiments theconnector 110 is an electrical connector. In such instances, theconnector 110 provides an electrical connection to one or moreelectrical conductors that extend along the length of the flexibleelongate member 102 and are electrically coupled to the component 108.In other embodiments, the connector 110 is an optical connector. In suchinstances, the connector 110 provides an optical connection to one ormore optical communication pathways (e.g., fiber optic cable) thatextend along the length of the flexible elongate member 102 and areoptically coupled to the component 108. Further, in some embodiments theconnector 110 provides both electrical and optical connections to bothelectrical conductor(s) and optical communication pathway(s) coupled tothe component 108. In that regard, it should be noted that component 108is comprised of a plurality of elements in some instances. The connector110 is configured to provide a physical connection to another device,either directly or indirectly. In some instances, the connector 110 isconfigured to facilitate wireless communication between theintravascular device 100 and another device. Generally, any current orfuture developed wireless protocol(s) may be utilized. In yet otherinstances, the connector 110 facilitates both physical and wirelessconnection to another device.

As noted above, in some instances the connector 110 provides aconnection between the component 108 of the intravascular device 100 andan external device. Accordingly, in some embodiments one or moreelectrical conductors, one or more optical pathways, and/or combinationsthereof extend along the length of the intravascular device 100 betweenthe connector 110 and the component 108 to facilitate communicationbetween the connector 110 and the component 108. Generally, any numberof electrical conductors, optical pathways, and/or combinations thereofcan extend along the length of the intravascular device 100 between theconnector 110 and the component 108. In some instances, between one andten electrical conductors and/or optical pathways extend along thelength of the intravascular device 100 between the connector 110 and thecomponent 108. The number of communication pathways and the number ofelectrical conductors and optical pathways is determined by the desiredfunctionality of the component 108 and the corresponding elements thatdefine component 108 to provide such functionality.

As shown in FIGS. 1 and 2, the intravascular device 100 includes atransition section 114 where the central portion 102 is coupled to thedistal portion 104. FIGS. 3-15 described below discuss various featuresof the transition section 114 in accordance with the present disclosure.In that regard, it is understood that the features described below forcoupling the central portion 102 and the distal portion 104 may besimilarly applied to couple any two parts of the intravascular device100 together, including (1) coupling any two of the central portion 102,the distal portion 104, and/or the proximal portion 106 together, (2)coupling two or more sections together that collectively define thecentral portion 102, the distal portion 104, and/or the proximal portion106; and/or (3) combinations of (1) and (2). While the followingdescription will focus on features of the transition section 114 in thecontext of a specific example of the central portion 102 and a specificexample of the distal portion 104, no limitation is intended thereby.Instead, it is understood that the concepts of the present disclosureare applicable to intravascular devices having various types ofproximal, distal, and central portions. In some particular instances,the transition section is utilized to couple two or more parts,components, sections, and/or portions similar to those described in oneor more of U.S. Pat. Nos. 5,125,137; 5,873,835; 6,106,476; 6,551,250;and U.S. patent application Ser. No. 13/931,052, published as U.S.Patent Application Publication No. 2014/0005543 on Jan. 2, 2014, U.S.patent application Ser. No. 14/135,117, published as U.S. PatentApplication Publication No. 2014/0180141 on Jun. 26, 2014, U.S. patentapplication Ser. No. 14/137,364, published as U.S. Patent ApplicationPublication No. 2014/0187980 on Jul. 3, 2014, and U.S. patentapplication Ser. No. 14/139,543, published as U.S. Patent ApplicationPublication No. 2014/0187984 on Jul. 3, 2014, U.S. patent applicationSer. No. 14/143,304, published as U.S. Patent Application PublicationNo. 2014/0187874 on Jul. 3, 2014, and U.S. Provisional PatentApplication No. 61/935,113, filed Feb. 3, 2014, each of which is herebyincorporated by reference in its entirety.

Referring now to FIGS. 3-15, shown therein are aspects of the transitionsection(s) of the intravascular devices of the present disclosure. Inthat regard, one of the major issues associated with existing functionalguide wires is poor mechanical performance as compared to frontlineguide wires. The transition section(s) of the present disclosurefacilitate (1) intravascular devices having improved mechanicalperformance; (2) selection of the best performance core material(s) fordifferent portions of the intravascular device; (3) a simplifiedmanufacturing process that allows for (a) one or more portions of theintravascular device to be completely assembled and tested as afunctional unit prior to attachment to the other portion(s) of theintravascular device, (b) the use of shorter, individual portions thatreduce the working space needed for assembly, and (c) reduction of theamount, and corresponding cost, of core wire and other components thatare scrapped during typical assembly; (4) the creation of a family ofintravascular devices where the particular portions/sections used toform the intravascular device may be selected and coupled together usingone or more transition sections based on the desired functionality ofthe intravascular device; (5) minimizing the amount of handling of eachportion/section throughout the build process because the differentportion/section can be manufactured/assembled separately and thencoupled together; and (6) simplifying the electrical/optical connectionprocess utilized to connect communication pathways betweenportions/sections by utilizing a uniform approach.

Referring more specifically to FIG. 3, as shown, the distal portion 104includes a core member 120 and a flexible element 122 according to anembodiment of the present disclosure. As shown, the core member 120 hasan outer diameter 124 that is less than an outer diameter 126 of theflexible element 122. In some instances, the outer diameter 126 of theflexible element 122 is the same or substantially the same as thedesired outer diameter of the intravascular device 100. Accordingly, insome particular embodiments the outer diameter 126 of the flexibleelement 122 is approximately 0.014″, such as between 0.0138″ and0.0142″. The flexible element 150 may be a coil, a polymer tubing, acoil-embedded polymer tubing, and/or combinations thereof. In thatregard, the flexible element 150 may comprise multiple components insome implementations. Though not shown in FIG. 3, the distal portion 104may also include a further flexible element extending distally from thecomponent 108 (or a housing containing component 108) to the distal tip105 of the intravascular device 100. Again, this distal flexible elementmay be a coil, a polymer tubing, and/or a coil-embedded polymer tubing.In some instances, the distal flexible element is radiopaque and/orincludes a radiopaque tip. In some implementations, a flow sensor ispositioned at the distal tip 105 of the intravascular device 100.Generally, the distal portion 104 of the intravascular device 100 mayinclude features similar to those described in any of the patents andapplications incorporated by reference above, but utilizing thetransition sections of the present disclosure described below.

The core member 120 can be formed of any suitable material such asstainless steel, nickel and titanium alloys (such as Nitinol andNiTiCo), polyetheretherketone, 304V stainless steel, MP35N, or othermetallic or polymeric materials. As discussed in greater detail below, aproximal section of the core member 120 includes an engagement structure128 that allows the core member 120 to be coupled with a core member 130of the central portion 102.

As also shown in FIG. 3, the central portion 102 includes a core member130 and an outer layer 132 according to an embodiment of the presentdisclosure. As shown, the core member 120 includes section 134 andsection 136 having different profiles. In particular, in the illustratedembodiment sections 134 and 136 have different outer diameters. In thatregard, section 136 has an outer diameter 138 that is less than an outerdiameter 140 of section 134. Similarly, the outer diameter 138 ofsection 136 is less than an outer diameter 142 of the outer layer 132.In some instances, the outer diameter 142 of the outer layer 132 is thesame or substantially the same as the desired outer diameter of theintravascular device 100. Accordingly, in some particular embodimentsthe outer diameter 142 of the outer layer 132 is approximately 0.014″,such as between 0.0138″ and 0.0142″.

The outer layer 132 includes conductors embedded therein. As discussedbelow, in the illustrated embodiments of the present disclosure, twoconductors are embedded within the outer layer 132 of the centralportion 102. In that regard, the conductors are fully encapsulated bythe material forming the outer layer 132, which is a polymer in someinstances. In some embodiments, an insulating layer—such as part of theouter layer 132 or a separate layer—is formed between the conductors andthe core member 130. To that end, the insulating layer can be utilizedto electrically isolate the conductors from the core member 130. As aresult, each of the conductors embedded in the outer layer 132 and/orthe core member 130 can be utilized as an independent electricalcommunication pathway of the intravascular device 100.

Each of the embedded conductors is formed of a conductive material, suchas copper, gold, silver, platinum, or other suitable conductivematerial. Generally, the size of the conductors is selected to allow theconductors to be fully embedded within the material forming the outerlayer 132. Accordingly, in some instances the conductor is between a 24AWG conductor and a 64 AWG conductor, with some embodiments utilizing 48AWG conductors. In other instances, larger or smaller conductors areutilized. In certain embodiments, the conductors are space substantiallyequally around a circumference of the central portion 102. However, theconductors may be embedded in any suitable manner and/or pattern,including symmetric, non-symmetric, geometric, and non-geometricpatterns. In some instances, the conductors are conductive ribbons thatallow for ease of connection and optimization of the coating wallthickness to maximize the core diameter.

The core member 130 can be formed of any suitable material such asstainless steel, nickel and titanium alloys (such as Nitinol andNiTiCo), polyetheretherketone, 304V stainless steel, MP35N, or othermetallic or polymeric materials. A distal section of the core member 130includes an engagement structure 144 that allows the core member 130 tobe coupled with the core member 120 of the distal portion 104.Generally, the engagement structures 128 and 144 serve to provide aphysical interface between the core members 120 and 130. In that regard,the engagement structures 128 and 144 can be utilized to facilitatetransfer of torque, pushing forces, and/or pulling forces between thecore members 120 and 130. Further, the engagement structures 128 and 144can be utilized to align the core member 120 and 130 with respect toeach other in one, two, or three dimensions. Accordingly, the engagementstructures 128 and 144 may include any combination of structuralfeatures to facilitate such alignment, including without limitationprojections, recesses, flats, tapers, curves/arcs, bends, lockingfeatures, and/or combinations thereof.

Referring now to FIGS. 4-6, shown therein are aspects of the engagementstructure 128 according to the present disclosure. In the illustratedembodiments of the present disclosure, the engagement structures 128 and144 have the same structural features and, therefore, engagementstructure 144 will not be described separately. However, in otherembodiments the engagement structures 128 and 144 have differentstructural features configured to mate with one another. As shown, theengagement structure 128 includes a flat 150 and a flat 152 that arestaggered from one another. In that regard, flat 150 is recessed agreater extent than flat 150. For example, in the illustrated embodimentflat 150 is positioned approximately 33% of the way through the coremember 120, whereas flat 152 is positioned approximately 67% of the waythrough the core member 120. The engagement structure 128 also includesa transition 154 between the flat 150 and the outer surface of the coremember 120. Similarly, the engagement structure 128 includes atransition 156 between the flat 150 and the flat 152. In the illustratedembodiment, the transitions 154 and 156 are curved or arcuate, but inother instances are tapered and/or stepped. In some instances, theengagement structure 128 is defined in the core member 120 by removingportions of the core member utilizing a suitable manufacturingtechnique, such as grinding, etching, laser ablation, and/orcombinations thereof. In other instances, the engagement structure 128is defined in the core member 120 as part of a molding process.

Referring again to FIG. 3, to couple the central portion 102 to thedistal portion 104 the engagement structures 128 and 144 are engagedwith one another. In particular, the flats 150 and 152 of the engagementstructure 128 are engaged with corresponding flats of the engagementstructure 144, as shown. Further, in order to provide the desiredalignment in the axial direction the central portion 102 and the distalportion 104 can be pulled away from each other such that the transition156 of the engagement structure 128 engages a corresponding transitionof the engagement structure 144. With the core members 120 and 130engaged via the engagement structures 128 and 144, a tubular member 160can be positioned around the engagement structures 128 and 144 to helpmaintain the relative positions of the core members 120 and 130. Thetubular member 160 can be formed of any suitable material, includingmetals and polymers, including without limitation 304V Stainless Steel,Nitinol, NiTiCo, and Polyimide. In some instances, the tubular member160 is a hypotube. Solder or adhesive can be flown into the interior ofthe tubular member 160 to fixedly secure the core members 120 and 130 toone another and to the tubular member 160. In that regard, the solder oradhesive will fill the gaps between the core members 120 and 130 andsurround the core members 120 and 130 within the tubular member 160 toprovide a solid physical connection between the components.

As shown in FIGS. 8A and 8B, the tubular member 160 can be initiallyplaced around the core member 120 at a position distal of the engagementstructure 128 to allow the engagement structures 128 and 144 to engageone another. Once the engagement structures 128 and 144 are engaged, thetubular member 160 can be translated proximally along core member 120,as shown by arrow 162, to a position surrounding the engaged engagementstructures 128 and 144. With the tubular member 160 positioned aroundthe engagement structures 128 and 144, the core members 120 and 130 canbe joined together using solder and/or adhesive. As noted above, in someinstances it is advantageous to provide slight tension to the coremembers 120 and 130 (e.g., by pulling them apart) when coupling themtogether. Note that a similar approach can be utilized where the tubularmember begins around core member 130 proximal of engagement structure144 and is then translated distally to surround the engaged engagementstructures 128 and 144. Further, it should be noted that the core member120 and 130 can be secured to one another by solder, adhesive, welding,etc. without the tubular member 160 positioned around the engagementstructures. Further, in some embodiments the intravascular device 100does not include tubular member 160, but may include other element(s) orstructure(s) to solidify the joint.

Referring now to FIG. 9-13, electrical conductors 170 and 172 of thedistal portion 104 have been electrically coupled to the embeddedconductors in the outer layer 132 of the central portion 102. In someembodiments, an insulating layer is formed around the core members 120and 130 and the tubular member 160 prior to extending the electricalconductors 170 and 172 over the exposed portions of the core members 120and 130 and the tubular member 160 for connection to the embeddedconductors. In that regard, the insulating layer serves to electricallyisolate the core members 120 and 130 and the tubular member 160 from theconductors 170 and 172. The insulating layer may be formed of anysuitable material. In some instances, the insulating layer is a polymerlayer. In some implementations, the insulating layer is a parylenelayer. Generally, the insulating layer may have any suitable thickness,but in some instances has a thickness between about 0.0001″ and about0.001″. In some instances, the conductors 170 and 172 are coated with aninsulating layer in addition to or in lieu of the insulating layeraround the core member 120 and 130 and the tubular member 160.

As shown in FIGS. 10 and 11, the tubular member 160 includes flattenedportions to allow the conductors 170 and 172 to extend along the outsideof the tubular member 160 without increasing the outer diameter of thetransition section 114 beyond the desired outer diameter of theintravascular device 100. For similar reasons, in some instances theconductors 170 and 172 have a rectangular, oval, rounded rectangularprofile, and/or flattened profile. As shown in FIG. 10, the conductor170 extends a long a flat 174 of the tubular member 160 and iselectrically coupled to an embedded conductor of the central portion 102at connection 176. The conductors 170 can be electrically coupled to theembedded conductor using any suitable techniques, including withoutlimitation solder, physical contact, an electric coupler, etc.Similarly, as shown in FIG. 11, the conductor 172 extends a long a flat178 of the tubular member 160 and is electrically coupled to an embeddedconductor of the central portion 102 at connection 180. The conductors172 can be electrically coupled to the embedded conductor using anysuitable techniques, including without limitation solder, physicalcontact, an electric coupler, etc.

In some implementations, the embedded conductors are exposed forelectrical coupling to conductors 170 and 172 by removing a portion ofthe outer layer 132 covering the embedded conductors for a certainlength along the longitudinal axis of the central portion 102. In someimplementations, the embedded conductors are exposed for electricalcoupling to conductors 170 and 172 at an end surface extendingperpendicular to the longitudinal axis of the central portion 102. Thatis, the embedded conductors are not exposed along the length of thecentral portion, but rather are exposed at an end surface of the outerlayer 132. FIG. 12 provides a perspective view of the tubular member 160that shows the flats 174 and 178. FIG. 13 provides a side view of thetransition section 114 showing the engagement of the core members 120and 130 within the tubular member 160 and the conductors 170 and 172extending over the tubular member 160.

Referring now to FIG. 14, an outer layer 182 is formed over theconductors 170, 172, the tubular member 160, and the core members 120and 130. In the illustrated embodiment, the outer layer 182 extendsalong the length of the intravascular device 100 between the centralportion 102 and the distal portion 104 a distance 184. As shown, thedistance 184 results in the outer layer 182 covering the transitionsection 114 and portions of each of the flexible element 122 of thedistal portion 104 and the outer layer 132 of the central portion 102.The outer layer 182 may cover a lesser amount of the transition section114 and/or greater or lesser amounts of the central portion 102 and/orthe distal portion 104 in other instances. The outer layer 182 can beformed of any suitable material. In some instances, the outer layer 182is a polymer material configured to seal the transition section 114. Theouter layer 182 is a PET shrink fit tubing in some instances. Anadhesive is placed inside the PET shrink fit tubing to ensure adequatemoisture barrier for the electrical connections in some implementations.In some instances, a coating is provided on at least a portion of theintravascular device 100, which may include the transition section 114.In that regard, the coating can be a suitable hydrophilic or hydrophobiccoating. In some implementations, the coating provides increasedlubricity. Exemplary coating materials include, without limitation, PTFEimpregnated polyimide, silicone-based coatings, and hydrophilic basedcoatings. Generally, the coating will be a very thin layer of material.For example, in some implementations the coating has a thickness lessthan about 0.0005″, less than about 0.0001″, and/or less than about0.00005″.

Referring now to FIG. 15, in some instances the transition section 114include a tubular member 190 and/or a tubular member 192. In thatregard, the tubular members 190 and 192 can be utilized to increase thediameter of the transition section 114 in the areas surrounding the coremembers 120 and/or 130. In that regard, in order to allow the tubularmember 160 to translate along the length of the core member 120 tofacilitate engagement of the core members 120 and 130 prior to thetubular member 160 being positioned around the engaged engagementstructures 128 and 144, a portion of the core member 120 having areduced outer diameter relative to the flexible element 122 and thetubular member 160 will be exposed between the flexible element 122 andthe tubular member 160. Similarly, a portion of the core member 130having a reduced outer diameter relative to the tubular member 160 andthe outer layer 132 may be exposed between the tubular member 160 andthe outer layer 132. Accordingly, tubular members 190 and 192 may beutilized to increase the diameters in these areas to reduce the overallvariability in the outer diameter of the transition section 114. In someinstances, the tubular members are polymer tubings. In someimplementations, the tubing is slit to allow for positioning over thecore member 130 after positioning the tubular member 160. In someparticular embodiments, the tubular members 190 and 192 are PET shrinkfit tubings. In some instances, only one of the tubular members 190 and192 is utilized.

The guide wires of the present disclosure can be connected to aninstrument, such as a computing device (e.g. a laptop, desktop, ortablet computer) or a physiology monitor, that converts the signalsreceived by the sensors into pressure and velocity readings. Theinstrument can further calculate Coronary Flow Reserve (CFR) andFractional Flow Reserve (FFR) and provide the readings and calculationsto a user via a user interface. In some embodiments, a user interactswith a visual interface to view images associated with the data obtainedby the intravascular devices of the present disclosure. Input from auser (e.g., parameters or a selection) are received by a processor in anelectronic device. The selection can be rendered into a visible display.

Persons skilled in the art will also recognize that the apparatus,systems, and methods described above can be modified in various ways.Accordingly, persons of ordinary skill in the art will appreciate thatthe embodiments encompassed by the present disclosure are not limited tothe particular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

What is claimed is:
 1. A sensing guide wire, comprising: a proximalassembly having a proximal core member, at least one proximal electricalconductor, a connector in electrical communication with the at least oneproximal electrical conductor, and a proximal outer layer encapsulatingat least a portion of the at least one proximal electrical conductor,wherein the proximal core member includes a first end section, whereinthe proximal outer layer insulates the at least one proximal electricalconductor from the proximal core member; a distal assembly differentfrom the proximal assembly, and coupled to the proximal assembly, thedistal assembly having a distal core member, a sensing element, and atleast one distal electrical conductor different from the proximalelectrical conductor and coupled to the sensing element, wherein thedistal core member includes a second end section, and wherein theproximal assembly and distal assembly are connected together such that:the second end section of the distal core member is coupled to the firstend section of the proximal core member at a first location, and the atleast one distal electrical conductor is coupled to the at least oneproximal electrical conductor at a second location to establishelectrical communication between the connector and the sensing elementvia the at least one distal electrical conductor and the at least oneproximal electrical conductor, wherein the first location and the secondlocation are proximate to one another; and a tubular member positionedaround the first and second end sections such that an intermediateportion of the guide wire includes the first and second end sections andthe tubular member.
 2. The guide wire of claim 1, wherein the sensingelement includes at least one of a pressure sensor or a flow sensor. 3.The guide wire of claim 1, wherein the tubular member is a hypotube. 4.The guide wire of claim 3, wherein the hypotube includes at least oneflat.
 5. The guide wire of claim 4, wherein the at least one distalelectrical conductor extends along the at least one flat of thehypotube.
 6. The guide wire of claim 4, wherein the hypotube includestwo flats, wherein the at least one distal electrical conductor includestwo distal electrical conductors, and wherein the two distal electricalconductors extend along the two flats of the hypotube.
 7. The guide wireof claim 1, wherein each of the proximal core member and the distal coremember is formed of at least one of 304V Stainless Steel, Nitinol,NiTiCo, and MP35N®.
 8. The guide wire of claim 7, wherein the distalcore member is formed of a different material than the proximal coremember.
 9. The guide wire of claim 1, wherein the distal assemblyincludes a first flexible element proximal of the sensing element and asecond flexible element distal of the sensing element.
 10. The guidewire of claim 9, wherein the first flexible element includes at leastone of a coil and a polymer tubing.
 11. The guide wire of claim 10,wherein the second flexible element includes at least one of a coil anda polymer tubing.
 12. The guide wire of claim 1, further comprising aninsulating coating extending over the portion of the guide wire thatincludes the first and second end sections, and the tubular member. 13.The guide wire of claim 1, wherein the guide wire has an outer diameterof approximately 0.014″, 0.018″, or 0.035″.
 14. The guide wire of claim1, wherein the proximal outer layer comprises a polymer material. 15.The guide wire of claim 1, wherein the proximal core member comprises afirst region distal to the proximal outer layer and a second regiondistal to the first region, wherein the second region comprises a firstdiameter, the first region comprises a second diameter greater than thefirst diameter, and the proximal outer layer comprises a third diametergreater than the second diameter, wherein the first end section formspart of the second region.
 16. The guide wire of claim 1, wherein thefirst end section comprises a distal engagement structure, and whereinthe second end section comprises a proximal engagement structure engagedwith the distal engagement structure.
 17. The guide wire of claim 16,wherein the distal engagement structure includes a flat that is engagedwith a flat of the proximal engagement structure.
 18. The guide wire ofclaim 16, wherein the distal engagement structure includes a projectionthat is engaged with a recess of the proximal engagement structure. 19.The guide wire of claim 1, wherein the at least one distal electricalconductor is electrically coupled to the at least one proximalelectrical conductor through a removed section of the proximal outerlayer.
 20. The guide wire of claim 19, wherein the first and second endsections are fixedly secured to one another within the tubular member byat least one of a solder or adhesive.
 21. A method of forming a sensingguide wire, the method comprising: providing a proximal assembly havinga proximal core member, at least one proximal electrical conductor, aconnector in electrical communication with the at least one proximalelectrical conductor, and a proximal outer layer encapsulating at leasta portion of the at least one proximal electrical conductor, wherein theproximal core member includes a first end section, wherein the proximalouter layer insulates the at least one proximal electrical conductorfrom the proximal core member; providing a distal assembly differentfrom the proximal assembly, and having a distal core member, a sensingelement, and at least one distal electrical conductor different from theproximal electrical conductor, and coupled to the sensing element,wherein the distal core member includes a second end section; andcoupling the proximal assembly to the distal assembly, including:securing the proximal core member to the distal core member, whereinsecuring the proximal core member to the distal core member includescoupling the first end section and the second end section at a firstlocation; coupling the at least one distal electrical conductor to theat least one proximal electrical conductor at a second location suchthat the connector is in electrical communication with the sensingelement via the at least one distal electrical conductor and the atleast one proximal electrical conductor, wherein the first location andthe second location are proximate to one another; and positioning atubular member around the first and second end sections such that anintermediate portion of the guide wire includes the first and second endsections and the tubular member.